Combined lightning arrester and resistance unit



Sept. 11, 1928.

1,683,783 c. J. KELLOWAY COMBINED LIGHTNING ARRESTER AND RESISTANCE UNIT Filed Jang 22, 1923 /QYLQ ATTORNEY Patented Sept. 1l, 1928.

PATE

NT OFFICE.

CHARLES J. KnLLowaY, or WILMINGTON, NORTH cARO'LiNA.v

` COMBINED LIGHTNING ARRESTER- AND RESISTANCE NIT.

applicati@ filed Jamiary tareas. serial No. 614,201.

My invention relates to combined lightning arresters and resistanceunits.V y

I will describe one form of unit embodying my invention, and will then point out the noVel'eat-ures thereofin claims.

`In thewaccompanying drawing7 Fig, lis a view, partially diagrammatic,,showing `in front elevation, one form of u nit embodying my invention and one 'form of electrical circuit forv use therewith. Fig. 2 isy a top view ot the unit shown in Fig. l. i. A.i

Similar' reference characters reterto -similar parts in each of the views. E.

Referring to the drawing` the reference character A designates a. block ot insulating material such as porcelain or glass. This block A is provided with a plurality of holes B through which aconductor C is threaded. The holes are so disposed that the conductor passes successively tromthe llower to the up# per side and from the upper side to the lower side of the block A. thus permittingportions ot the conductor C to be exposed on two sun As here shown `there are taces ottheblock. three'rows otholes B, and the conductor threaded through these holes in such manner y G of binding post Il.

that the conductor comprises three rows connected in series. One end ot conductor C` is connected with a suitable binding post l-l by ineansot a plate Dto which this conductor is fastened by` a Vscrew D. The other endv oi the conductOrC isconnected with' av second bindingpostI. The stemsv otthese-two binding posts which are inserted in suitable recesses A? in the bottom of theblock A whichrecesses are thereafter filled with sealing compound as at 5, Fig. l.

It is clear,

therefore, that conductor C, thus threaded through the insulating block A, may be considered as aresista'nce unit, of this conductor which and the portions C l protrude from the upper surface ot block A may be usedxas taps to Vvary the resistance ot the unit. This is accomplished as Jr'ollows:

The connecting plate D rests on the top surface ot a lug A on block A, which surface is bevelled so that this plate slopes as indicated in Fig. l. A fiat spring member provided near one end with a hole to accommodate the stem ot binding post H. The member E is held in place adjacent plate D by means of a block F having a. rounded lower surface which block is forced into enmember E by the nut gagement with springr The spring member H and I are provided with heads EisV E vis also provided with a plurality oilllongitudinally extending slots 1,2 and 3, A contact shoe J is provided with a. stem J which may beinserted `in anyone ot these slots and may be restrained in any given position by means ot anutJ2 threaded on this stem J. Y, Since the upper surface of the lug Af is bevelled, shoe .J is forced into Contact. .with `the taps CA with considerable pressure when nut G is tightened.Vv

' It is clear that by movingshoeJ tothe right or lett in the proper slot ot member E any desired amount ot resistance may be out in or out, thus making-it possible to effect a wide range ot resistance within t-he limit ot the conductor C. A y

The porcelain block A ismou ted upon a base plate L by means ot screw Kand the 'stem of a binding post M. interposed be-` tweenbase pla-tef'L and blo'ckfA is` a thin sheet Q otsome suitable material having ,a very high resistance such as carborundum." As shownin `the drawing,y this earborundum sheet makes electrical contact with conductor VC at each point P. f

ln operation any required portion of the conductor is included in anwelectrical cir cuit,pas in series with a source ot energy such as abattery O andan electro-responsive device as arlamp R. 4This connection is eftecte'dby binding posts H andI. Base pla-te L, which dis in contact with the underside of carborundum Ysheet Q., 'isY connected to the ground by means otbindingpost Under theintluence of direct Acurrentfor alternating current of 'relatively low fre' `quency and volta-ge, the Zig-zag or tortuous shapeof conductor Chas relatively little effect so that the tendency of sueh'currents to flow through the high resistance plate Q tov groundis negligible. A .lightning discharge, however, being an oscillating current ot relatively high trequency `and voltage, seeks the shortest path to groundeven it the resistance of such path is comparatively high, and so when such afdischarge enters the unit from veither wire 10 or 11. itpasses through the first which it encounters and then goes directly through plate Q to ground.- charge is thus dissipated without causing damage to the other apparatus in circuit with the protective device.

Combined lightning arresters and resistors are particularly adapted for, thoughin no constructed in accordance with my inventionV strand ot conductor -C Such a dis ilu Way limited to, application to railway signaling circuits .for protecting the signaling apparat-us againstfailu1e due to burned out resisters during and as a result of electrical storms in the vicinity.

Although I have herein shownl and described only one form of unit embodying my invention, it is understood that various ends connected With saidterininals, adjustable means for shuntinglout any desired portion of said'` conductor, a member of relatively hivh resistance lincontact with a pluralityo points along said conductor, and means f for connecting said member with ground. l A' 2". In combination, an insulating block provided With a plurality ofholes therein, a resistancelwire,threaded through said holes therebyy allowing' portions of said Wire to form taps protruding from tivo faces of said block, means for -selectively engagingsaid taps on one ysaid `face for' varying thefeieetive length of said wire, an electricaly circuitvineluding said means' and a portionof said wire`,fand a sheet of carborundum havL ing one sidein contact with' the saidl tapsl on tlieremaining face of saidbloek and its other side connected with the ground.

3. In combination,r a block. of insulating material, a conductor thread'edth/rough said block and' protrudine therefrom onL two opposite faces Inova l l adapted toenvage'with said conductor on one Vface of said `block, and means for connect-- ing said conductoron.y the other side' of said leV Contact V4apparatus block wit-ll ground through a high resistance.

4. In combination, anv insulating block having an upstanding lug thereon, a resistor inserted in said block `andprotruding at intervals therefrom to form taps, a spring member supported by saidrlug and adjacent said resistor, and a contact shoe interposed between said member and said block and adapted to engage said taps, a conducting plate connected with the ground', and a member of, high electricall resistance' interposed betweensaid plate andsaid block and Amaking contact With said plate land'said resi stor.

Y V5. In combination, a'bloekprovided with two yterminals for conneetionwith an electrieal circuit, a conductor of resimance'lnaterial threaded 'through said bloelt to In'o'vide a relatively tortuous ath for electric current and having its enV is connected'fwith said its lends connected Withsaidfterminals, a mov'- able Vshoe electrcallyconnect'cd with one said terminal and arranged tov Contact withy any one of a plurality of points along said conductor whereby a variable amount of thecon ductor may be shunted, a :member ofrelati-vely high resistance. inl Contact with a1 plurality Vof points along said condnctonand means for connecting said menfiber with'ground. o In testimony WhereofI ailiX 'my signature CHARLES J'. KELLOWAY. 

